Chemical Disaster of Methyl Isocyanate Leakage

Yang, Hyuk Jun; Choi, Jung Myung

Abstract

BACKGROUND: We are in the edge of some human made disasters such as hazardous materials and air pollution, for example, the world news reported that the city of Bhopal, India had serious victims related with a leaking out of the chemical materials, Methyl Isocyanate and many people in India were killed by. These situations many people who live in this world are worrying about are not others, but just ours and people consider about that kind of the disasters are the possible situation to happen to all the people. Therefore, we performed this basic study to recognize the risk of Methyl Isocyanate leak accident and to prepare local disaster plan with EMS system. METHOD: Trace 8.0, a simulation software made by the U.S. company Safer System was used as a tool to estimate the diffusion distance, area and its victims at the concentrations of 0.02 ppm, 0.2 ppm, 5 ppm respectively for an assumed B-city of 2 hundred thousands population count in which was presumed 500 kg Methyl Isocyanate gas to leak out.
RESULTS
1. During 1 hour, maximum diffusion distances of 0.02 ppm, 0.2 ppm, and 5 ppm were 5.41 km, 1.61 km and 0.29 km respectively on the plume impact. 2. Maximum population counts influenced by Methyl Isocyanate gas at the concentrations of 0.02 ppm, 0.2 ppm, and 5 ppm were 40,838, 4,346 and 222 on the plume impact, while those were 138,238, 17,261, and 1,588 on the vulnerability impact, respectively. 3. Therefore, 17,261 persons must put on respiratory device and 138,283 persons must be evacuated to safety place within 1 hour.
CONCLUSIONS
Only small amount leak of Methyl Isocyanate may cause tremendous chemical disaster in urban area, so its disaster plan must be prepared with an accident simulation program and Material Safety Data Sheets (MSDS). Especially, nearby emergency center of an industrial complex must have a strong position about preparation of chemical disaster plan and perform a disaster drill of hazardous material accident annually.